Ok, my thread isn't here, I will start over then.

I have asked this question in the RX-8 forum and searched with no success.

I have heard that the RX-8 6 spd Transmission is the Transmission used in the 6spd miata. Is this true? If not, what differences are there between the two? Thanks for any info y'all have.

Sincerely,
Jason C. Williams

 

the diff is the bellhousing
i've heard the same thing, rx8 trannys are miata trany made to fit a rotary
they sucks and cant hold more than 300hp (this is what i've heard)

 

Only fair since the Miata 5-speed is the same unit introduced on the '78 RX-7 and used on all N/A RX-7s (as well as the 1st-gen Turbo).

 

Why are the 6 speeds so expen$ive?

Would a 1st gen bellhousing fit a Miata 6 speed?

 

Besides the fact they are not as comman as the 5spds, I think they are expensive just because people are willing to pay lots for them... "oooh look at me I have 6 gears how many do you have?"

 

i dont think so, you might wanna try to find a renesis tranny and get ur driveshaft machined to fit it. but the tranny is weak and wont last long with bigger torque numbers than what FDs are able to set stock. (from what i've read/heard)

 

No.

The "bellhousing" on the 1st-gen/N/A FC is actually the front half of the transmission case. You could swap this onto a Miata (or other low-power '78-up Mazda RWD) 4- or 5-speed transmission to attach a rotary.

However the 6-speed unit is nothing at all related to the Mazda "smoothcase". It's made by Aisin and is a completely different design, and housings are non-interchangeable.

edit: to the post directly above... the RX-8 6-speed *is* the Miata 6-speed. I don't know gear ratios offhand but it's the same unit, just different bellhousing bolt pattern.

 

The RX8 six speed is supposedly a stronger version of the miata six speed. I do agree with them being weak though.

Here it is as wriiten in the RX8 book by Jack Yamaguchi:

The Type Y6M 6spd transmission is a reinforced, high-torque version of the transmission first employed in the MX-5 Miata, developed jointly by Aisin-AI and Mazda, and manufactured and supplied by Aisin.
The transmission has a direct (1.000:1) 5th ratio, combined with an overdrive 6th of 0.843. The lower four ratios are 1st 3.760. 2nd 2.269. 3rd 1.645 and 4th 1.187. New in the Y6M are triple-synchronizers on the first three ratios, versus the MX-5's first and second gears. All other gears are fitted with single-cone synchronizers.

 

that's a nice tight 3rd to 5th set of ratios.

 

That 2nd gear would make an awesome 1st.